The present invention relates to inkjet printers and, more specifically, to the detection of ink leakage in a print head of such a printer.
Inkjet and like printers and cartridges are known in the art and include those made by Hewlett-Packard, Canon and Epson, amongst others. Inkjet printers include an ink supply and a print head to which ink is delivered for controlled discharge. Typically, an inkjet print head includes a substrate on or in which an expulsion mechanism is formed, a barrier plate that provides channels for delivering ink to the expulsion mechanism and an orifice plate positioned over the barrier layer such that ink is expelled through openings in the orifice plate. Power supply lines and signal processing or control lines are coupled to componentry in or on the substrate.
A disadvantage of known inkjet print head arrangements, however, is that the ink used therein is generally invasive and with time will leak outside of its confined area. For example, ink may leak in between the substrate and barrier layer or between the barrier layer and orifice plate, amongst other leakage channels. The escaped ink may seep onto the interconnect region(s) of the substrate where it can cause a short between the power and control lines or otherwise cause a malfunction of the print head.
Hence, a need exists for detecting when ink in an inkjet print head has escaped its confined area and may cause a malfunction of the print head. Furthermore, a need exists for a print head ink leakage detector that can be implemented in an economical, non-overly complex manner.
Accordingly, it is an object of the present invention to provide an inkjet print head that includes a mechanism that detects when ink has escaped its confined space.
It is another object of the present invention to provide such a print head that (1) can be economically implemented and (2) can uniquely identify itself when it has failed.
It is another object of the present invention to provide such a print head that utilizes conductive material adjacent the power and/or control lines to detect undesired leakage.
It is also an object of the present invention to provide an inkjet printer that incorporates such a print head.
These and related objects of the present invention are achieved by use of a ink leakage detecting apparatus as described herein.
The attainment of the foregoing and related advantages and features of the invention should be more readily apparent to those skilled in the art, after review of the following more detailed description of the invention taken together with the drawings.